Mycogeography

Cosmopolitan
and pan-tropical species

A number of fungi are widespread through human agency (such as unintended dispersal
through trade) and there are some examples such fungi in the IMPORTS,
EXPORTS AND PUZZLES SECTION. However, there are also many species which
were naturally widespread long before humans started transporting fungi. In
this section you'll find examples of fungi, found in Australia, which are naturally
very widespread. Some of them are cosmopolitan (or virtually so), while others,
the pantropical species, are found through most of the tropical areas of the
world.

You should remember that while a cosmopolitan species is widespread, that is
not the same as saying it turns up everywhere. Many fungi have specific host,
substrate or habitat preferences. For example, Podaxis pistillaris
is a cosmopolitan species, but in dry habitats.

Cosmopolitan

Schizophyllum commune

Trametes versicolor

A good example of widespread distribution is the superficially mushroom-like
Schizophyllum commune. This species is found on all continents except
Antarctica, growing on wood of all sorts.

The polypore Trametes versicolor is also known from all continents except
Antarctica. It is very common in Australia and has been described as probably
the commonest wood-rotting polypore in American forests In North America it
has been given the common name of Turkey Tail, the banded colours being reminiscent
of the bands of colour on the tail feathers of turkeys.

Panellus stypticus
is a small, nondescript, creamy to yellow-brown mushroom found growing on dead
wood. The stem is very short, and often towards one side of the cap, rather
than being central. The morphological evidence (using both macroscopic and microscopic
structural features) indicates that this species is found in Australasia, parts
of Asia and temperate areas in the northern hemisphere.

The morphological evidence is supported by mating tests that show there is
just the one species in all these areas. While it is all the one species, DNA
evidence shows that, genetically, there are six distinct geographical groups:
eastern North America, western North America+Asia, Europe, southeast Australia,
Tasmania, New Zealand. Note that western North America and Asia are given as
one group because the western North American examples of the species are genetically
closer to the Asian representatives than to those in eastern North America.
Why is this so? The Rocky Mountains, which began forming in the Cretaceous period,
may have prevented (or at least greatly limited) the gene flow between representatives
of the species in western and eastern North America. On the other hand, the
land-bridge across the Bering Strait allowed gene flow over a long period, possibly
up to as recently as 10,000 years ago. The DNA evidence strongly supports the
idea that the species originated in the northern hemisphere, though the evidence
cannot determine whether in North America or Eurasia. It seems likely that the
species reached ancient Australasia through Asia, possibly through one, or a
few, founder events. New Zealand was the last area in Australasia to be colonised
by the fungus (well after New Zealand had separated from Australia), quite likely
via another founder event.

The Panellus study is an example where geological knowledge, classical
morphological fungal taxonomy, mating
tests and DNA studies have been brought together to elucidate the history and
travels of a species.

As a group, the corticioid fungi (with their flattish, sheet-like fruiting
bodies) are found world-wide and many of the individual corticioid species are
cosmopolitan. Examples are Botryobasidium subcoronatum,
Botryobasidium botryosum,
Coniophora olivacea
and Dacryobolus sudans.
The Shaggy Inkcap (Coprinus comatus),
Coprinus disseminatus,
Marasmius oreades
and Volvariella speciosa
are examples of cosmopolitan, mushroom-producing fungi. Amongst the ascomycetes
Leotia lubrica
is found in all non-polar continents and Trichoglossum walteriappears
to be similarly widespread (except possibly for Africa). The bracket-like Stereum
ostrea,
with its smooth underside, is a cosmopolitan stereoid species and Polyporus
arcularius
is another example of a cosmopolitan polypore. Cyathus stercoreus
is an example of a Birds Nest Fungus found in most areas of the world, on dung
or enriched soil. The so-called Cannonball fungus (Sphaerobolus stellatus)
with its 2mm diameter cups (each with a single "egg") is also found
in most areas of the world, on soil or rotting wood.

Within the genus Pycnoporus there are three species, all producing bright
orange, bracket-like fruiting bodies. In general terms Pycnoporus cinnabarinus
is found throughout the temperate areas of the northern hemisphere, Pycnoporus
sanguineus in the tropical and sub-tropical areas and Pycnoporus coccineus
in the temperate areas of the southern hemisphere.

Pantropical species

Hexagonia tenuis

A number of fungi are found in all tropical areas of the world - America, Asia,
Australasia and Africa. The polypores Earliella scabrosa and Hexagonia
tenuis are found throughout the tropical areas of the world, with the Hexagonia
being probably the most common polypore in the tropics. In Australia, as well
as being common in the tropics, it is also found on the Australian east coast
at least as far south as Jervis Bay.

The genus Cookeina produces small, stalked cup-like fruiting bodies
with the cups usually no more than about two centimetres in diameter. This is
a pantropical genus and Cookeina sulcipes, shown in the Cooke painting
at the top of this page, is an example of a species of this genus that is found
in northern Australia.

There are also some species which, though predominantly found throughout the
tropics, also spread turn up in some temperate areas. Examples are Dacryopinax
spathularia,
Ganoderma australe
and Amauroderma rude.
The last of these is found in a number of temperate areas of the southern hemisphere.
In fact, the original description (published in 1839) was based on a specimen
collected from Tasmania. Leucocoprinus birnbaumii
is another example of a tropical/sub-tropical fungus with temperate occurrences.
However, in the cooler areas it is confined to glasshouses or indoor pot plants
and so has presumably been introduced into temperate areas by humans. In Canberra
it appears in most years in some of the glasshouses at the Australian National
Botanic Gardens and has also been found in indoor pots in various suburbs.